Tech / General Engine Is your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!

good alternator not charging

Thread Tools
 
Search this Thread
 
Old 05-03-2011, 12:15 AM
  #1  
Junior Member
Thread Starter
 
dusting901's Avatar
 
Join Date: Aug 2010
Location: rob-ville
Posts: 49
Likes: 0
Received 0 Likes on 0 Posts
Car: 1974 caprice
Engine: tpi 400
Transmission: turbo 350
Axle/Gears: i was robbed of this knowledge
good alternator not charging

i swear this cars never gonna run right. 1974 caprice with a tpi 400 with the original 74 belt system

2 different brand new 3 wire internal regulated alt neither work
both tested at autozone and there good
new battery
12v at output stud
12v at thicker red wire of 2 wire connector

not charging at 14v it makes just enough voltage to keep the car idling which is about 12.25

EXTREMELY annoyed with this car seeing as im 18 been working on it for a year and a half and still dont have a working first car. the back seat is like a couch i just wanna lay some pipe down in it.
Old 05-03-2011, 12:17 AM
  #2  
Junior Member
Thread Starter
 
dusting901's Avatar
 
Join Date: Aug 2010
Location: rob-ville
Posts: 49
Likes: 0
Received 0 Likes on 0 Posts
Car: 1974 caprice
Engine: tpi 400
Transmission: turbo 350
Axle/Gears: i was robbed of this knowledge
Re: good alternator not charging

oh yeah and i can see the alternator turning on and slowing the belt down when i touch the brown wire to the + and sometimes it happens when i touch it to ground
Old 05-03-2011, 06:21 AM
  #3  
Supreme Member

iTrader: (1)
 
sofakingdom's Avatar
 
Join Date: Sep 2005
Posts: 26,122
Received 1,688 Likes on 1,283 Posts
Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: good alternator not charging

Does the "Gen" light in the dash come on when you turn the key to On with the engine not running?

If not, replace the bulb.

If the bulb goes bad the alt will never "know" that the key is even on, and won't do anything.

Old 05-03-2011, 11:49 AM
  #4  
Junior Member
Thread Starter
 
dusting901's Avatar
 
Join Date: Aug 2010
Location: rob-ville
Posts: 49
Likes: 0
Received 0 Likes on 0 Posts
Car: 1974 caprice
Engine: tpi 400
Transmission: turbo 350
Axle/Gears: i was robbed of this knowledge
Re: good alternator not charging

When the key is in the on posistion and when the problem started it used to be dim with the car idling and turn off with the rpm rising now its just off when the motors on and on with the key in on
Old 05-03-2011, 11:51 AM
  #5  
Junior Member
Thread Starter
 
dusting901's Avatar
 
Join Date: Aug 2010
Location: rob-ville
Posts: 49
Likes: 0
Received 0 Likes on 0 Posts
Car: 1974 caprice
Engine: tpi 400
Transmission: turbo 350
Axle/Gears: i was robbed of this knowledge
Re: good alternator not charging

Thats my car same color 4dr vinyl
Old 05-03-2011, 03:16 PM
  #6  
Junior Member
 
Curious_George's Avatar
 
Join Date: Nov 2008
Location: Lake Mary
Posts: 75
Likes: 0
Received 0 Likes on 0 Posts
Car: '87 IROC, '92 & 99 Corvette Vert.
Engine: L98, LT1, LS1
Transmission: L98 = 700R4
Axle/Gears: L98 = 3.23 G92
Re: good alternator not charging

What type of alternator do you have? I would guess a 10 / 12 SI?
Old 05-03-2011, 06:00 PM
  #7  
Junior Member
Thread Starter
 
dusting901's Avatar
 
Join Date: Aug 2010
Location: rob-ville
Posts: 49
Likes: 0
Received 0 Likes on 0 Posts
Car: 1974 caprice
Engine: tpi 400
Transmission: turbo 350
Axle/Gears: i was robbed of this knowledge
Re: good alternator not charging

One is a autozone duralast 10si other is a ebay 100 amp 10si
Old 05-03-2011, 08:00 PM
  #8  
Junior Member
 
Curious_George's Avatar
 
Join Date: Nov 2008
Location: Lake Mary
Posts: 75
Likes: 0
Received 0 Likes on 0 Posts
Car: '87 IROC, '92 & 99 Corvette Vert.
Engine: L98, LT1, LS1
Transmission: L98 = 700R4
Axle/Gears: L98 = 3.23 G92
Re: good alternator not charging

Originally Posted by dusting901
One is a autozone duralast 10si other is a ebay 100 amp 10si
Try troubleshooting what you have with this link...

http://www.oldengine.org/unfaq/10si.htm

CG
Old 05-03-2011, 10:09 PM
  #9  
Junior Member
Thread Starter
 
dusting901's Avatar
 
Join Date: Aug 2010
Location: rob-ville
Posts: 49
Likes: 0
Received 0 Likes on 0 Posts
Car: 1974 caprice
Engine: tpi 400
Transmission: turbo 350
Axle/Gears: i was robbed of this knowledge
Re: good alternator not charging

I got the 2 terminal going to the battery post the battery post straight to + and the 1 terminal (indicator light) going to the indicator light. I know for a fact that this is not a wiring problem.

I read somewhere that autozone tests alternators without load on the so a alternator operating at 50% would come up good i hope this is true i feel like this problem is too simple

I figure ill buy a brand new alternator and return the duralast 1 and see what happens
Old 05-04-2011, 06:06 AM
  #10  
Junior Member
 
Curious_George's Avatar
 
Join Date: Nov 2008
Location: Lake Mary
Posts: 75
Likes: 0
Received 0 Likes on 0 Posts
Car: '87 IROC, '92 & 99 Corvette Vert.
Engine: L98, LT1, LS1
Transmission: L98 = 700R4
Axle/Gears: L98 = 3.23 G92
Re: good alternator not charging

Well don't say you know anything is 100% until it is working (Bad Karma) )

When the key is ON, make sure you have 12V at terminal 1 of the alternator harness / wire. Also, make sure the idiot light / bulb in the dash is the RIGHT bulb, not just "a" bulb.

CG
Old 05-04-2011, 08:50 AM
  #11  
Junior Member
Thread Starter
 
dusting901's Avatar
 
Join Date: Aug 2010
Location: rob-ville
Posts: 49
Likes: 0
Received 0 Likes on 0 Posts
Car: 1974 caprice
Engine: tpi 400
Transmission: turbo 350
Axle/Gears: i was robbed of this knowledge
Re: good alternator not charging

Yeah 12 v and yeah ther the right bulbs
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
RazorN8
Tech / General Engine
4
01-07-2022 11:44 AM
Ikes 91Z
LTX and LSX
21
12-09-2015 03:49 PM
Navy8125
Engine/Drivetrain/Suspension Parts for Sale
10
08-22-2015 07:13 PM
Dialed_In
Firebirds for Sale
2
08-20-2015 01:45 PM



Quick Reply: good alternator not charging



All times are GMT -5. The time now is 08:17 PM.